Permutation lock



Nov. 20, 1951 H. c. MILLER 2,575,574

PERMUTA'TION LOCK' Filed March 2e,k 1949 f s sheets-sheet 1 big/MillaNov. 20,519,511., H. c. MILLER PERMUTATION-LOCK 3 Sheets-Sheet 2 FiledMar-ch .26, 1949 n INVENTOR.

a/zlyjlillel' ATTORNEYS NOV. H.. Q MILLER 2,575,674

` PERMUTATION Locx Filed Marchv 26, 1949 3 Sheets-Sheet .'5

I N VEN TOR.

Patented Nov. 20, 1951 UNITE-D STAT-Es PAT-:ENT

-PERIYITATION LOCK Harri;1 '-0.1Miller, Fair-fai, Va.

ApplicationMarc'h 26, 19'49, 'Serial'Nm l83,5413

"-13 Claims. (C1.170-'129) This invention relates to improvements'inpermutation locks, commonly referred to as combination locks.

Locksof the type commonly referred to as combination locks are, ofcourse, verywell known. Also it is generally known that such locksdepend for -their operation upon the alignment of .a plurality ofelements in a preselected manner which permits the .operation of a bolt.'These elements-are usuallyinthe form o'f discs, common- 'ly calledtumblers., each of which is provided with a notch .or recess, calledagate, the alignment lof thegate determining when the bolt .can be moved.'It `is common for these `locks .to b e provided with three discs,.although more coul'd be used. .'I'hesecurityof such locks isdependen'tupon the factthat the number of-orders or permutations of the possible.relative positions .of each disc .before all ofthe .gatescome intoregister, which gives the correct combination, is so large that thechances of thesenotches or gates being aligned by a person not familiarwith .the combinationis so small vas to be negligible.

The tumblersare operated through 4meansbf a driver wheel which alsohasaspecial gate. .An element called a ffence extends transversely acrossthe edges of all .of .the ftumblers and :is adapted to drop into thegates when all of the gates in the tumblers are Vin alignment and whenthe driver wheel is manipulated to permit the fence to drop.Conventionally, thefence is -held in such a position .that kit isslightly `spaced from the outer peripheries of all of .the tumblers.However, because of the difficulty in manufacture, it is almostimpossible to manufacture all of the parts, including the tumblers, tosuch close tolerances that there will be the sameslight difference inthe space between the outer edges of the dilerent tumblers and the`fence. Accordingly, by ,a

very carfeul manipulation of the driver wheel to a position such thatthe fence drops against .the edge of the highest tumbler, a skilledperson can detect by feel-o1- by a very minute sound or click kwhen oneof the gates is aligned with the vfence.

Then by continuing .to .manipulate the -driver wheel by means ofthedial, thegatefof thenext highest tumbler `can be aligned with the -fenceand, therefore, with the gate of the iirst tumbler and so on until thecorrect combinationis found and the security of thelock is broken.Accordgate the driver Wheel. Furthermore, the 'special -gate can beopened 'only when this Adriver wheel gate is substantiallyaligned-withthe-fence. This'avoids the defect of lthe'prior `devices that the driver'wheel cannot 'be 1 turned -suciently to manipulate the tumblers whenthe'ga'te is open. Also, in order to Ainsure that 'the tumblers carnnotbe vibratedor walkedbyoscillatingthe driver wheel over its limited arc.of'movementfinterlocking means aregprovidednthe form ofserra'tions onthe "fence and -ontheperipheries 10i tthe-tum blers so that `as soon gasthe 'driver wheel gate is opened the `fence 'rests on -the Ytumblers,the serrations being linter-#engaged 'thereby manipulation 'oi'.thetumblers practicallyimpcs-f sible.

The Iprimary object ,or thepresentinvention is to provideracombinationflockin which a'manipulation of the .dial will-not jgiveany-indicationftf the position of thegates'in'anyof 'the'tumblers.Another Objectis `to provide a combinationlock with `a driver wheelhaving'means for `selectively f closing thelgateinthe 'driverwheel'andfor per# mitting rotation or the driver wheel `only when the gate isclosed sothatthefence isheId-away from theperipheries ofthe tumblers.

Another yobject jis )to provide -a combination lock in which .the driverWheelcannotbe rotated to manipulate'thetumblers When'the driver .Wheelgate is open.

Another o bj ect vis lto lprovide a combinationjlocl in which 'the`driver wheel ,cannot be -rotated to' manipulate the .tumblers when 'thedriver 'Wheel gate 'is open and having interlocking means `be tween `thetumblers ,and thejfenee to prevent'the walking of the ,tumblers when thedriver wheel gate is open.

,A still Afurther..oblectis toprovide .an improved combination lookinwhichithe Afence can be held in `spaced relation ito vthe Aouter edgesof all ,0L

' the tumblers untilthegates iniallofthe tuniblers4 are broughtintoalignment.

.Another .Objectis .,tocvercome defects of prior combination ,locks .by.providing means which holds .theience -in slightly spaced relation withrespect tothe edgesfof thetumblers, .which,meanscan only be .operatedrwhen .the,gates.inthe vari- Other and further objectswillbecome.lteadill'J apparent feller-.ning description when consideredin connection. with the accompanying drawings, illustrating anembodiment of the invention, and in which:

Figure 1 is a vertical section on line I-i of Figure 2 of a loclrmade inaccordance with the present invention;

Figure 2 is the vertical section of Figure l; and

Figure 3 is a Vpartial vertical section showing the parts of the lockin-a dierent position from that shown in Figure 2;

Figure 4 is a partial sectional view on line 4-4 of Figure 1;

Figure 5 is a partial sectional view on line 5'-5 of Figure 2;

Figurt 6 is a partial View showing a modified form of the gate closingmeans;

Figure 7 is a View similar to Figure 6 showing the modified driver wheelin a diierent position; and

Figure 8 is an exploded perspective view of the modied driver wheel andgate closing means.

Figures 9 to 11 inclusive, are partial views showing various positionsof the key-operated gateclosing means and showing the relative positionsof the fence; and y Figure l2 is a partial vertical section showing theengagement of the fence with one of the tumblers, near its gate.

The illustrative drawings show a conventional combination lock modied insuch a manner as to permit the application of an embodiment of on line2--2 the'present invention. The conventional lock.

comprises ...a casing I connected by a press t to a hollow sleeve 2which projects through a door 3. In the casing a plurality of tumblers6, 1 and 8 are rotatably mountedon a cylindrical boss integral with thecasing, the boss being substantially co-extensive with the sleeve 2.Secured to the outer end of the sleeve 2 is a suitable escutcheon plate9. The casing is secured to the door 3 by the sleeve 2 and suitablescrews. Inside the sleeve 2 is a shaft II, the inner end of which hasrotatably iixed thereto a driver wheel I2, the opposite end of the shaftIl having a dial I3 xed thereto. As will be more clearly explainedhereinafter the dial and its hub constitute the means through which thetumblers 6, 1 and 8 of the combination lock are manipulated.

Each of the tumblers 6, 1 and 8 are of conventional construction and aredivided in two parts, an inner part serving as a hub and an outer parthaving a suitable notch or gate 6a, 1a., and 8a, respectively, it beingunderstood that all of the gates of the tumblers must be in properalignment in order to operate the bolt of the lock. Conventional meansare provided for changing the relative position between the hub portionand the outer portion of the tumblers for the purpose of changing thelock combination. Suitable xed washers having small detents which engagea recess 2a in the sleeve 2 are placed between the hubs of adjacenttumblers so that from the standpoint of mechanical friction each of thetumblers is completely isolated from the other. One of such washers isindicated at I6. Between one side of the washer and the next adjacenttumbler is a flyer I1 having an outwardly projecting detent I1a. Theannular portion of the flyer I1 serves as a spacer while the outwardlyprojecting detent I1a serves as an element through which one of thetumblers is driven by a laterally projecting detent on the next adjacenttumbler. This construction just described in general is conventional andtherefore further details are not considered necessary. l

The driver wheel I2 is screw-threadedly secured to the shaft I I and asuitable key 2I is provided to lock the driver wheel in non-rotatableposition on the shaft I I. The driver wheel is provided with a lateralprojection 22 which is adapted to engage the outwardly extending detenton the yer between it and the tumbler 8. It will be readily understoodthat when the dial I3 is rotated to rotate the driver wheel I2 that theprojection 22 will drive the tumbler 8 and through the intermediatefiyer between the tumbler 8 and tumbler 1 the latter will be driven andso on, including the tumbler 6. It will also be well understood that thegates Ba, 1a and 8a of the respective tumblers may be brought toregister with each other in the well known manner when the propercombination is obtained by turning the knob I3 rst to the right, liningup the gate in one tumbler, then to the left lining up the gate in thesecond tumbler, and then to the right again lining up the third tumbler,and so on, ir" a lock with more than three tumblers is used.

The lock is provided with a bolt 23 which is adapted to slide in asuitable guide formed in the casing I, the bolt 23 being operated by afencelever 24 pivotally attached thereto by a screw 26. A suitablespring 30 is'provided for the purpose of urging the fence-lever 24toward the tumblers. The fence-lever 24 is provided with a laterallyprojecting arm, commonly referred to as a fence 21, which is adapted toengage the gates when the tumblers are in proper relative positions. Thedriver Wheel I2 is also provided with a special gate I2a, the shape ofwhich is complemental to the shape of a depending boss 28 on thefencelever 24. The lower point of the boss 28 normally rides on theouter periphery of the driver wheel I2. The periphery of the driverwheel I 2 and the size of the boss 28 is such that the fence 21 isslightly spaced from the outer periphery of all of the tumblers. As isusual, the lock is provided With a suitable device to prevent tamperingso that in the event that an attempt is made to drive the shaft I Iinwardly toward the casing, the bolt 23 would be locked in position. Tothis end. a suitable element 3l having an end portion 3Ia which engagesthe outer face of the upper tumbler 8 is provided. The element .3| ispivoted on screw 33 and is provided with a curved end 3Ib whichpartially encircles a locking pin 34 when the parts of the lock are innormal position. The locking pin 34 is adapted to slide in a suitableguiding recess in the casing I and is provided with a C- shaped washerwhich engages a groove in the pin 34. One side of the washer engages thecurved end portion 3Ib of the element 3l and a suitable spring 31 isprovided for normally urging the pin 34 in upward position where itcould engage a notch in the underside of bolt 23. It will be readilyapparent that in the event the end 3Ia of the element 3| is moved, aswhen an unauthorized person attempted to disturb the parts of the lock,the element 3| would pivot around the screw -33 and its opposite end 3Ibwould become disengaged from the washer 36, thereby permitting thespring 31 to urge the locking pin 34 into such a position as to engagethe recess in the underside of the bolt 23 so that the latter could notbe moved.

The construction described so far is conventional. The presentinventional resides in the modification of the driver wheel I2 andcertain other parts and the provision of a slide 43 Vwhich can beselectively controlled for closing the gate I2a in the driver wheel I2so that a person not familiarwth the combination cannotmanipuisqto'fthefcombination l ofthe lock. ":Io this end,

theoutside of .the 'driver'wheel--has Jaiiiired` thereto spaced AguidesI411 and 42. These :guides are undercut fas fait I'a and 42o-to Aprovide.mar- .inal edges Which-overlapfaslide M3. lThe-slide 43 comprisesJan-'arcuate portion 33a which has exactlythefsame radius as the'remaining Lperipheral 'surface of fthe Ydriver 'wheel t2, 'itwo legs band #13e Eand-asecon'd transverse portion 43d Jlziihg'ithe oppositevrends -of the legs. The inner Side if rleg 45431) provided Iv'ritlri:gear teeth M which are adapted to :mesh with 4`a -sxnall pinion 16 itclconstitute a rackand -pini'on movement, -the rotation fof the pim'on146 icontrollin'g the 'radial movement of the slide 4-3. The pinion 66is xed tofa #shaft i41 "which -ex'tends through -a bore intionalrconStruction-rotatablyimounted inthe hub 6T 'the fdial |33-, is-i'xed :to fthe outer end of xthe lraftlu. As -clearly shown in FigureTl, thebarrel d! the Llock I8 -is provided with a series l"of pins 5I ofdfEerent lengths 'which are adapted to be aligned with a Isecond-pluralitylof pins S2-which are mounted in the radial recesses o'fthehub of the jdial 13. The pins 52 -arespring loaded so that `they farenormally 'urged Ytoward the 'barrel o'fithe lock-'inthe usual fmanner.When the key 53 "is 'Jncitdnfthelbarrelpsomefof the pins152'will extendA#across -the -dividing line between the barrel and the inside of thev-hub 'to provide 'an nterlockbetweenthe 'barreland the hub-wherebyth'eshaft 41 wllfbelccke'd with thevdial I3. -Ac cordingly, 1rotationfof the vldial vIl3 'will rotate the driver Wheel I 2 vvhlhih`turndrives' the 'tumbler's in the Pm'anner already described. Asfinrconventiona'l `cylimirical pin "tumbler 'ltype locks, 'thekey2canfonly'he removed and inserted when the tunibler in-one position.lIn the immediate instance'lthe zero -positionfefithe -lock'is such thatthe pinion 416 will 4have unoved 'the slide 43 to rits radiallyoutermost 'position where l`its outer arcuate -surface '43a -coincides'with the outer periphery fof the driver'vvheel I2. This is clearlyshown A1in Figure-13. Tt -willbe f-rea'dily seen that Whenthe s1ide-43isinthis position the gate I'Za isflos'ed and `thafen'ce I21' Ican' notffall or he urged by the spring "30 intor fthe gates Vof the tumblersbecause sthe boss 21B-of 'the fence-lever -24 will 4be preventedby Itheslide 4:3 from falling into its corresponding gate fin-the-driver'vvheelI-2. The slzepfit'hedriverlwheel I2 'and the `length of the boss 284issuch 'that the Vfence-lever-l2ll is held in such ia position 1thatthe -fence'21 cannot vtouch the tuinbl'ers unless'the slide -'Iltisdropped to 'open gate 112e. However, assuming -the gates of the tumblersare in registry, if now the key 53 is inserted in -the lock -48 andshaft 41 is rotated to manipulate the pinion :'46 to withdraw the 'slide$3'fradial1y inwardly as shown in Figure 12, the

' fence will enter .theigates so that the bolt 123 Scan be vwithdrawn byturning the driver wheel in a counter-clockwise :direction -as viewed inFigures 2-and3. From Figures land-'2 itwill be readily seen 'thatthefcover -I'a of the casing'is provided with 4suitableus'tops to limitthe rotation oi the driver'whe'el il`2. -As Fshown ran arcuateboss 6U isprovided, "the edges 60a and 68h of which constitutefthe stopswhich'limit the rotationrof the driver Wheel whentheslide 43 is movedradially infsucha position'that 'theportion-il-d ofthe slide projectsbeyond .fthe router 'periphery ofthe driver wheel @M illtwill be seenthat ivvhen the slide 43 is fin 'fthe withdrawn .position the driverwheel I21carm'0tbe lrotated sufficiently to .manipulate relative amountof limited rotation fthe :same

theftumblers. Howevergthellimitsof rotatoniare such as to--permitisuicient rotation -of drivery f wheel I2to1withdraw boli-23.

It will be apparent vthat the pin-tumbler 'loek 48 `is -`notessential tothe .present invention; 'the lock -48 merely ladds :a measure 4ofisecurity -because the `slide control mechanism :cannot "be operated'unless the shaft 1 .lis :unlocked from 'the hollow shraft -I I lOn ltheother hand, if ldesired, a :second combination -icould :be substitutedfor the pin-tumbler lock 18.

The lock 48 4does,'hovvever,addiareal measure of security Abecause -the:stops on the casing I'a permit rotation of the-driver wheel `I2 .onlyover a :limited are, and .-should ione be -able :to 'pick the lock118anddropftheslidef43,:the driver wheel I2 l'cannot be rotatedsufficiently to manipulate the-tumblers. Thenin-orderto rotate thedriver wheel `vl2 it is necessary to return the gate 'to originalA.position and this `.will put the tumbler of lock -48 in suchavposition that itwould again have to be picked in order v-to 'manipulatethe tumblers 6, 1 and 8 and the slide 3 at the fsame time. v

A :modified lform oit -the slide foperating .'nech-V anism is shown in-Figures 4'6,"1-1and18. In this form a special driver 'wheelf12 having-the usual gate 80,is provided with laterally-disposedundercut guides12a and 112D. `'The -undercut :guides are adapted to receive the sidesofra l'-slide '13, theigeneral outside shape of which 4is similari/a theslide 43, previously fdescribed. One lateral edgeof the slide -isprovided with an elongated recess 13a which is adapted to `.permitlimited relative movement with respect lto a lscrew A11i in the driverwheel 12. The purpose of thescrew. and slot arrangement 'iis to *preventAthe :slide 'i3 'from becoming disassembled from the guides on the sidesof 'the-driver wheel 12. The driver' wheel `12 'is provided with 'arecess 16 which .is adapted to be engaged by a l'spring pressed 'ball11. A suitable recess 18 'in jthe Vlower end of the slide13 is adapted`to Vreceive 'a spring '19 tand the lloall 11. It willbereadily'apparent that :when the =slide 13 is assembled-under' thelateral fguides of the driver wheel 1-3 'the `spring '19 will press theball 11 into the recess 16 `when theslide is in one position.

Itis important that 'the radii o'f 'the farcuate surfaces 13b and 13oof'the slide l'43 be exactly the same as the radius-of the outersurfaceof the driver wheel '12. This will be apparent in view df -th'efact that-'the primary purpose of the lslide 13 is to close the gate 80of the driver wheel12.

itis important that when the slide 1113 is in 'such position 'relativeto the driver wheel 12 that 'the arcuate surfaces 13b and 13e be-inregistrywith the periphery of the driver Wheel 12 so 'there will :be'no unevenness in the surface on which the 'boss 28 of the fence-lever24 rides and so that the'position of the gate 8D will not be indicatedin any manner by any manipulation "of the driver 'wheel 12. It is tobeunderstoodthat the driver wheel`12 is provided with a lateral detent22 through which the tumblers of the lock are to be operated in themanner previously mentioned. y

.As shown .in dottedoutline the cover for .the casingis provided with.inwardly .projecting ybosses which limit the rotational movement of thedriver Wheel 1-2 whenlthe-slide 1:3 is'ina position so that the arcuatesurface 13o projects beyond theouter :periphery'ofthe-.driver wheel 12.The

andere and for the same reasons as that described in connectionA withthe first embodiment.

The construction of this modied form so far described is very similar tothat of the previous form. The main dierence between the two forms isthat in the modified form the slide controlling mechanism is betteradapted to the movements of the conventional pin tumbler type lock wherethe tumbler must be turned substantially 360 between the key-insertingposition and the unlocking position. The main advantage of the modifiedform is that there is a minimum of lost motion between the cam and thegate when it is in the most essential position.

To this end, the slide 13 is provided with an opening 83 of the peculiarshape shownin the drawings. This opening 83 is adapted to cooperate Withthe slide cam 84 which is xed to the end of the shaft 41 by means of aflattened area 41a and a complementary D-shaped hole 81 in the cam. Thecam 84 is held on the end of the shaft 41 by means of the screw 88 whichengages the end of the shaft. The opening 83 comprises an arcuateportion which extends between points 98 and 9|, the radius of thisportion being substantially the same as the radius of the outer surface84a of the cam 84. The center of this radius is coincident with thecenter of the arcuate surface 84a when the slide 13 is in the positionshown in Figure 6. The shape of the opening immediately below the point9| is more or less immaterial so long as it clears the arcuate surface84h. The rectangular recess 92 is of sufcient extent in both dimensionsas to accommodate the entrance of the tang portion 85 of the cam 84.

For an explanation of the operation of the slide controlling mechanismof the modied form, attention is invited to Figures 6 and 7, 9, l0 and11. In Figure 6 the slide 13 is shown in the depressed positionpermitting the boss 28 to drop into the gate 88 in the driver wheel 12and with the tang 85 of the cam slide 84 in the position shown, the pintumbler lock 48 will be in such a position to permit the insertion andremoval of the key. In Figure '1 the slide 13 is shown'in a positionsuch that the arcuate surface 13b bridges the'v gate 88 so that the boss28 holds the fence-lever 24 in the uppermost position with the fence 21spaced from the outer periphery of the tumblers. When the slide 13 is inthis position the driver wheel 12 can be rotated to all positionswithout the fence 21 dropping down on to the tumblers.

The progressive positions of the tang 85 in operating the slide 13 toopen the gate 80 are shown in Figures 9, and l1. Going back to Figures 6and 7 it will be noted that in Figure 6 the slide 13 is in the lowermostposition uncovering the gate 88 and the tang 85 is in the upperposition. When the tang is in this position the pin tumbler of the lock48 will be in such a position that the key can be inserted and removed.

` It will be noted that the slide cam 84 can be rotated in a clockwisedirection and when the cam is rotated approximately ninety7 degrees thelower edge of the arcuate surface 84h will engage the underside of thenotch 92 and the slide 13 will move toward the closed position.Continued rotation of the slide cam 84 in the clockwise direction, asshown in Figures 9 and l0, will cause the edge of the tang 85 tothereafter engage the underside of the notch 92 so that continuedrotation will cause the slide to move toward the 8 surface 84a3justclears the corner edge of the notch 92. Atthis pointztheslide .13 willbe in the gate-closing position and the ball 11. will snap into therecess 16., thus holding the slide 13` in that position. 'I'he pintumbler can be rotated further until the lower edge of the surface 84hengages the lower recess in the opening 8.3. It will be readilyunderstood that when the tang 85 is rotated in counter-clockwisedirection that the tang will engage the lower side of the notch 92 tomove the slide to the lowermost position and the spring pressed ballwill engage the driver wheel 12 thereby applying suiicient friction tohold the slide in the position so that the surface 13e projects beyondthe periphery of the driver wheel 12.

. When the slide 13 is in the latter position the sides of the slidewill engage the edges of arcuate bosses 92 and 93 which are carried onthe lock casing in the manner previously described. The purpose forlimiting the rotation of the driver wheel is the same as that mentionedin connection with the previous embodiment. y

In order to assure that the tumblers cannot be walked around byoscillating the driver wheel 12 through the limited arc permitted by thestop mechanism, the outer periphery of the tumblers are provided withcontinuous serrations |00 which are adapted to be engaged by a series ofcomplemental serrations |01 on the underside of the fence 21. When theslide closes the gate in the driver wheel the boss 28 will prevent thefence from engaging the outer periphery of the tumblers and for purposesof illustration in the practical embodiment of the invention the fence21 will be sepaced about one-thirty-second of an inchfrom the outer edgeof the serrations in the tumblers. As will be very clear from Figures 9and 10, the outer periphery of the driver Wheel 12 is provided with arelieved area 15 extending between the edge of the gate 88 and the slide13.A 'I'he purpose of this relieved area is to provide clearance betweenthe boss. 28 and the driver;

wheel 12 when the slide 13 is in the withdrawn position. Although thedimension is not absolutely critical in a practical embodiment of theinvention the construction is designed so that there will be a clearanceof about one-sixty-` fourth of an inchbetween the boss 28 and therelieved area of the driver Wheel periphery. It will be seen from thisthat no manipulation of the driver wheel 12 will make it possible towalk the tumblers in an attempt to open the lock. The engagement betweenthe serrations on the fence 21 and the peripheries of the tumblers willinsure that the tumblers cannot be rotated by any..

other means.

Figure 12 illustrates the manner in which the seen that when the slidecloses the gate thefence 21 will be spaced from the tumblers and.

when the slide 13 is dropped so that the fence rests on the tumblers theboss 28 cannot touch the edge of the gate 88 in the driver wheel 12. Thedepth of the serrations is greater than the normal manufacturerstolerance in the tumblers so that regardless of whether or not thegate-closing slide is used it would be extremely difficult to locate*position shown in Figures 7 and 11 until the 1| the gatesinthe tumblersby any k1ndofmanipu It W111- the inventive concept.

9 lation. of the driverl Wheel. It will be noted from Figure` 12 that'inj view of the inclined surfaces on the laterali edgesvoflthef gateand'gon the; fence itfw'ouidf be extremely dimcuitftonote any differencein feel or any minute click' unless the fence can. drop all theway intothegates ofthe tumblers and, ofcourse, this can happen only when all ofthe tumbler gates are in registry.

It is to be understood that'the embodiment of the invention shown inFigures 1 to 5 inclusive is identical in operation and in generalconstruction with that ofthe part of the invention shown in theremaining figures except for the mechanism which operates the slide 413of the r'st embodiment and the slide 12 of the second embodiment. Inother words, the driver wheel l2; of the rst embodiment is provided witha relieved 'area l5 which corresponds to the' relieved area 15 apparentfrom the above description that if desired a manually releasablemechanical connection could be provided between the hub of. theA dial-I'3 and the shaft 41 Without utilizing: a lock 48. For instance, a dogclutch could be provided so that normally' the shaft' 41 would rotatewith Lthe dial I3, the dog` clutch being manually releasable so that theshaft 4'1 could be rotated independently ofthe shaft I'I- for thepurpose of controlling the position of the gate.

From the foregoingdescription it will be seen that the present inventionprovides an improvemen-t in combination locks which greatly adds to thesecurity thereof and which is very inexpensive to manufacture. Althoughthe invention has been describedV in' considerable detail, it will be.apparentto those skilled in the art that many variations are possiblewithout' departing from It is therefore desired that the inventionnotbe'- limited except insofar as ismade necessary by the' appended claims.

What is claimed is:

l.. A combination lock comprising selectively adjustable tumblers. eachhaving a peripheral recess, a bolt,` a spindle having fixed thereto adriver wheel for adjusting' said tumblers, a lever pivotally connectedto said bolt, said lever having a laterally extending fence adapted tolie transversely across the faces of the peripheries of said tumblersand said lever also having a portion adapted to lie over and engage theperiphery of said driver wheel, said driver wheel havinga peripheralrecess adapted to receive said portion of said lever to perm-it saidfence to engage said tumbler recesses when the latter are adjusted toregister with said fence for moving said bolt and interlock meansnormally preventing said fence from engaging said tumbler rer cessesduring adjustment of the latter having actuating means selectivelyoperative'following adjustment of said tumbler recesses into registryfor rendering said interlock means inoperative to preventinterengagement of said fence and tumbler recesses. A

2. A combination lock comprising a plurality of selectively adjustabletumblers each having a I6 peripheral recess, a bolt, spindle meanshaving fixed thereto a driver wheel for adjusting said tumblers andlfor-actuating said bolt,v alever pivotally connected Ato, said .boltand having tumbler-engaging fence and a driver wheel-engaging' portion,said driver Wheel having a peripheral recess adapted to receive saidwheel-engaging portion of said lever when saidf recesses in saidtumblers are adjusted to register with said fence, and means movablymounted on said driver wheel and intercoupled with said spindle means tobe actuated therethrough for selectively bridging said peripheral recesssaid driver Wheel during adjustment-of said tumblers;

3. The combination as setforth claim 2, in which said bridging means ismovable radially of said driverwheel. Y

4. The combination as set forth in claim 2, together with means forlimiting rotation of said driver wheel when said lever is engaged insaid recess in said' driverY Wheel.

51 A combination lock comprising selectively adjustable tumbler wheelseach having a recess in the periphery thereof, a bolt, spindle meanshaving affixed thereto a driver wheel provided with a peripheral recessfor adjusting said tumbler' wheels and. for actuating said bolt, a leverpivotally connected to said bolt and engageable with said driver wheelfor actuating said bolt when said recessesl in said tumbler wheels areadjusted to register with said fence, and meansy movably mounted on saiddriver wheel and intercoupled with said spindle meansl to: be actuatedtherethrough for' selectively barring engagement of said lever with theperipheral recess of said driver' wheel. duringv adjustment of saidtumbler Wheels andactuated through said intercoupling on registry of'said tumbler wheels to permit said lever to engage said driver wheel'peripheral recess.

6. The.v combination asset forth in claim 5r and means for limitingrotational movement of. said driver wheel. when said lever is engagedin. said recess in. said driver wheel.

7. A combination lock. comprising.- selectively adjustable tumblers.each having a peripheral recess, a bolt, a. lever pivotedto said` bolt,spindleY means provided withy means for adjustingsaid wheels and forengaging saidflever. in one position for moving said bolt, said leverhaving a laterally extending; fence adapted to` lie transversely ottheperipheries of said tumblers andv adapted toengage the recesses insaidtumblers when thalatter are in registry and. interlock meansintercoupled through said spindle means normally preventing said fencefrom engaging said tumbler recesses during adjustment of the latter toestablish the combination and actuated through said spindle meansfollowing alignment of said tumbler recesses to render the interlockmeans inoperative to bar interengagement of said tumbler recesses andfence.

8. A combination lock comprising selectively adjustable tumblers eachhaving a peripheral recess, a bolt, a spindle having fixed thereto adriver wheel for adjusting said tumblers, a lever plvotally connected tosaid bolt, said lever having a laterally extending fence adapted to lietransversely of the peripheries of said tumbers and said lever alsohaving a portion to lie over and engage the periphery of said driverwheel, said driver wheel having an annular peripheral portion and arelieved portion provided with a recess adapted to receive said portionof said lever to permit said fence to engage said tumbler rec es'seswhen the latter are adjusted to register with said fence for movingsaidvbolt, the peripheries of said tumblersfbeing provided-with acontinuous series of serrations and said fence being provided withserrations adaptedv to engage the serrations on said tumblers, therelationship of the annular peripheral portion of said driver wheel andsaid portion on said lever being such that when said portion engagessaid annular portion of said Wheel the serrations on said fence will bedisengaged from the serrations on said tumblers, said relieved portionbeing so proportioned as to permit engagement between said serrations onsaid fence and said tumblers while said portion on said lever clearssaid relieved portion. A

9. A combination lock comprisingaplurality of Aselectivelyadjustabletumblers each having a peripheral recess, a bolt, a hollow spindlehaving -lfixed thereto a driver wheel for adjusting said tumblers andfor actuating said bolt, a lever pivotally connected to said bolt andhaving a tumbler `engaging fence and a driver wheel engage ing portion,said driver wheel havinga .peripheral recess adapted to receive saidwheel engaging portion when said -recesses in said tumblers are adjustedto register with said fence, a shaft extending through said spindle andmeans operably associated with said shaft for selectively bridging saidperipheral recess in said driver wheel.

10. A combination lock comprising a plurality of selectively adjustabletumblers each having a peripheral recess, a bolt, a hollow spindlehaving iixed thereto a driver wheel for adjusting said tumblers and foractuating said bolt, a lever pivotally connected to said bolt and havinga tumbler engaging fence and a driver wheel engaging portion, saiddriver wheel having a peripheral recess adapted to receive said wheelengaging portion when said recesses in saidtumblers are adjusted toregister with said fence, said driver wheel having a bridging slidemovable radially oi.'

said wheel, said slide having an arcuate surface adapted to bridge saidperipheral recess in said driver wheel, a shaft extending through saidhollow spindle and means operably associated between said shaft and saidslide for moving the` latter radially of said wheel.

1l.-A combination lock comprising a casing adapted to be attached to adoor, said lock comprising selectively adjustable tumblers each having aperipheral recess, a locking bolt, a spindle projecting from said casingand adapted to extend through said door, the outer end of said spindlehaving secured thereto a manually operable dial, the other end of saidspindle hav-` ing nxed thereto a driver wheel for adjusting saidtumblers and foractuating said bolt, a lever pivotally connected to saidbolt and having a tumbler engaging fence and a driver wheel engagingportion, said driver wheel having a peripheral recess adapted to receivesaid wheel engaging portion of said lever when said recesses in saidtumblers are adjusted to register with said fence, means for selectivelybridging said peripheral recess in said driver Wheel, a shaft extendingthrough said spindle and operably associated with said means forselectively bridging said recess in said driver wheel. l

-12. A combination as set forth in claim 11,.p1us means forl lockingsaid y shaft to` said hollow spindle.

13. A combination lock comprising a casing adapted to be attached to adoor, said lock comprising selectively adjustable tumblers eachhaving aperipheral recess, a locking bolt, a spindle projecting from said casingand adapted to extend through said door, the outer end of said spindlehaving secured thereto a manually operable dial, the other end of saidspindle having fixed thereto a driver wheel for adjusting said tumblersand for actuating said bolt, a lever pivotally connected to said boltand having a tumbler engaging fence and a driver wheel engaging portion,said driver wheel having a peripheral recess adapted to receive saidwheel engaging portion of said lever when said recesses in said tumblersare adjusted to register with said fence, said driver wheel having aslide movable radially of said driver wheel, saidslide having an arcuateportion of the same radius as the outer periphery of said driver wheeland adapted to bridge said recess in said driver wheel when in oneposition, a shaft extending through said spindle, means operablyassociated between said shaft and said slide for causing radial movementthereof and locked means for xing said shaft for selectively xing saidshaft for rotation with said spindle. HARRY C. MILLER.

REFERENCES CITED The following references are of record in thefile ofthis patent:

UNITED STATES PATENTS

